There is much
worrying and discussion about air travel. The experienced problems
are presently mostly related to terrorist threats and the
delays/annoyances caused by the seemingly necessary security control.
The argumentation in these seemingly endless discussions rarely try
to come to the roots of the problem, but we will go for the roots
now.

The experienced
problems with the common passenger airplanes are due to:

The explosion
sensitivity: It is too easy for a passenger to smuggle along a
little bomb which can cause the plane to fall down.

The inability to
fly slowly: The long runways needed banish airports to way outside
the central bus/metro networks they should have been located within.

We
might also mention the noisiness of the engines. VTOL
planes (with Vertical Take-Off and Landing) can slow down to a
standstill, and they may become usable for mass transport, but also
these are noisy. The noisiness increases the banishing effect.

In addition to the
problems experienced by the passengers, there is the important
problem of sustainability, pertaining mainly to CO2
emission and other pollutions. The proposed airship design will
strongly decrease these emissions – particularly when using
solar powered operation. Big airships may be regarded as
opportunities for being able to employ big and powerful solar energy
collectors.

These
environmental issues are certainly very important, but there is
widespread awareness and rational thinking about atmospheric
emissions, so we will now mainly deal with aviation aspects for which
illusions are prevalent: Does our craving for speed and power give us
real speed? Or does it just give us hassles, time waste and dangers?

High speed
airplanes don't save us much time, as much time is wasted on security
control, technical problems, and on getting to and from those awkward
airports. This is due to the fact that this technology implies a
balancing on the edge. Many technical factors are critical: The
integrity of the (explosion sensitive) airplane body, the air traffic
control (of planes unable to slow down), the integrity of landing
wheels and the surface they must roll on (so rapidly), the highly
trained personnel (able to operate at the technical edge), and so on.

In contrast to
this, we have the airship, lifted by gas buoyancy. It is less
explosion sensitive than a plane, and can glide to and hover near a
city center. We have now a race between the tortoise and the hare,
where the hare, as we know too well, has a hazardous labyrinth to
deal with.

It may be
difficult for space age minds to think rationally about airships, but
various suggestions for improvement will now be presented.

Huge investments
and infrastructure changes will be needed for replacing the planes,
but we needn't worry about that. Our alternative can start out as a
funny cruise alternative, and then gradually, due to its flexibility
and simplicity, transform itself from a recreational toy into a
serious transport tool.

The main features
of the following design are the abilities to:

transform the
airship shape between a fast mode and a safer mode (with parachute
shape)

grab a mooring
cable and align the ship along it

have exchangeable
modular balloons which may also store chemical and/or mechanical
energy

be driven by
solar energy

have a modular
payload, using e.g. exchangeable passenger cabins and battery packs

Part
II:

A
Multi-mode Airship

Airships
differ strongly in steerability: from the simple balloon which just
drifts with the wind, to the more or less rigid dirigible which can
be controlled in defiance of the wind. The multi-mode airship to be
proposed here is adjustable in this respect: It can hover or cruise
slowly, safely and quietly, and it can transform itself into a more
compact and rigid ship, less influenced by the wind and capable of
higher speeds.

The
Design

This
airship is essentially a paraglider
with three balloons attached under its canopy. Hanging under it is a
payload-carrying frame. This frame can hold one or more passenger
cabins. Various kinds of modules can be attached in the payload
frame. There will normally be a cockpit module fore and a battery
module aft. The modules should be able to slide along the frame –
for load balancing and pitch neutralization.

Airship,
fully opened.The canopy will normally be more closed fore and aft
– perhaps down to the center of each balloon.The top
propellers are protected against the cable by the M-shaped cable
catcher.

A
passenger cabin is ready to be attached into the payload frame,
between the cockpit and the battery module

The
propellers are here positioned for hovering (or for pressing a too
light airship down towards the ground)

Each
end of the long payload frame has a propulsion unit with propellers
in its ends, driven by electrical motors located in the middle of the
freely rotatable propulsion unit body. The canopy may be covered with
flexible solar
cells (polymer
or nanocrystal), connected to charge the battery module.

The
straps under which the payload frame is hanging, can be wound up on
reels inside the long side tubes of the frame, so that the airship
can transform itself between being a paraglider/parachute (with the
straps fully unwound) and a quite rigid airship, capable of higher
speeds and less wind-sensitivity (with the straps tightened).

The
fore and aft straps are ropes running through the fore and aft edges
of the paraglider screen. If these ropes are tightened while in
paraglider mode, the screen becomes like a parachute, decreasing the
forward movement of the airship. If they are tightened while in rigid
mode (with closed canopy) the airship gets a more aerodynamic shape.

Two
(or all three) of the balloons should be filled with helium. This may
give enough buoyancy for take-off when only the cockpit module is
used, but when a passenger cabin is attached, the motors on the
payload frame are needed for take-off. We are consequently talking
about a hybrid airship. These are easier to control during windy
take-off and landing than a pure (fully balloon-lifted) airship, and
the payload needn't constantly be balanced against the gas buoyancy.
A solid ground contact can be ensured if the motors are reversed, so
that they push the payload down towards the ground.

The
middle balloon might be filled with a combustible gas like methane –
or perhaps hydrogen. This balloon will then serve as a fuel tank for
the motor mounted on top of the airship. Methane has half the
buoyancy of helium, but is more easily obtainable. Natural gas is
essentially methane, but with also a little ethane and other heavier
gases, so this will be cheap and practical.

The
lightness of these fuel gases means the fuel will contribute to
lifting rather than having to be wasted on lifting itself. Their
rather lowbuoyancy has the advantage that the
weight and buoyancy of the airship don't change much as the fuel is
consumed. If a still more stable buoyancy is needed, ethane can be
used as fuel. It is about 3 % heavier than air, so when ethane in the
middle balloon has been burned up, the buoyancy of the airship has
changed only 1 %.

Mode
Shifting

When
the airship is fully opened, it functions as a motorized paraglider.
The balloons will keep the canopy raised, and the top motor will keep
the ship up against the wind. This may be the preferred operating
mode during slow cruising, at least when the wind is moderate. When
higher speeds are needed, the airship can tighten its straps to
become more rigid and aerodynamic. This tension will also press the
fuel gas out to the top motor. The airship can also take off and land
in the closed mode. This will be most practical if the wind is
strong. Tight closing can also reduce the balloon volume somewhat –
for buoyancy control.

The
open mode will be good for emergency situations: Whenever the airship
experiences a problem with staying airborne, it just loosens its
straps to descend slowly like a parachute or (with also the fore and
aft straps loosened) glide like a paraglider.

Airships
– open and closed.The rightmost one has also emptied its
middle (fuel gas) balloon.

An
additional possible mode is: hot air balloon mode – if the
airship is equipped with a simple balloon for hot air. This can be
stored in a box (with a burner and its fuel tank) lying upon the
middle part of the payload frame. When it is to be inflated, hot air
is first blown into it by a blower. When the hot air is able to hold
up the top of the balloon, a simple fuel burner suffices for
completing the inflation process and for keeping the airship
airborne. As the fully opened airship already defines the volume to
be occupied by the hot air balloon, this balloon can be a very simple
one which merely expands to fill the volume between the straps and
under the gas balloons (which should be elastic, or have a low
initial pressure, to allow for some additional expansion caused by
the heat from below). One or more horizontal straps between the two
fore straps, and similarly between the two aft straps, may be used
for giving fore and aft containment to the hot air balloon.

Propulsion
and Steering

The airship has
two different propulsion systems:

The motors
of the top propellers burn gas from the central balloon. It gives
its force near the balloons, where it is needed during forward
flight, and also is needed for pulling the airship up against the
wind while in paraglider mode. This remote-controlled propulsion
unit can also be turned to the sides for steering.

Each end
of the payload frame has a propulsion unit with propellers in its
ends, driven by electric motors located in the middle of the freely
rotatable propulsion unit body. A propulsion unit can place its
propellers in horizontal orientation for altitude changes, like
during VTOL operation. (Vertical Take-Off and Landing) The
propellers can then be swung to a vertical position for forward (or
backward) flight. The propellers can also be swung sideways for
steering.The electric motors enable the airship to operate also
if the air contains much dust (like under vulcanic eruptions) –
unlike ordinary aircraft, which must be grounded under such
conditions.

deal
with the forces: connecting payload weight to balloon buoyancy, and
retaining an aerodynamically efficient form in spite of air forces

Placing
simple balloons under a paraglider canopy assigns these two tasks to
two easily separable module types. Balloons are easily damaged and
worn out, e.g. by chemical influences compromising the gas tightness
of the light fabric, or by e.g. bullet holes. It is then advantageous
to be able to exchange simple balloon modules which need little of
the complex force distribution structures, and to be able to do this
without performing complex surgery in a closed airship body. Some
sort of Velcro-like patches may be enough for keeping the balloons in
place under the paraglider.

Energy
Storage

The
simplest way to store electrical energy is to use a battery pack,
which should be mounted as a module aft in the payload frame.
Lithium-ion
batteries have very high energy density, but are very expensive.
Molten
salt batteries (like Zebra batteries) gives almost the same
energy density at a lower cost, but these batteries must be heated to
about 300°C.
This should not be a problem in a professional and planned operation.
The battery heating may be done while lithium-ion batteries are used
for the first part of the flight.

Another
alternative is to store energy in flywheels.
They are normally designed to be compact, but a large carbon-fiber
flywheel (connected to a motor-generator) could be suspended inside a
balloon, where it would be well shielded against disturbances.

Flywheels
normally operate in a vacuum in order to minimize air drag losses. It
might be practical to have a lightweight vacuum sphere in this well
protected environment. But if the flywheel runs in helium, the drag
will be far weaker than in air. And if the helium is heated by lost
flywheel energy, it will become still lighter (provided its balloon
can expand somewhat), so the energy isn't really lost.

Mooring

Mooring
has traditionally been an awkward and labor demanding part of airship
operation, but in airship harbors having horizontal mooring cables,
mooring should be possible without any help from the ground. This
operation would be more reliable if the mooring place has
windscreens, such as vertical sails a little larger than an airship.

The
straight top is an important feature of the airship which is prepared
for easy and secure mooring, as this can align with a horizontal
mooring cable. Another important feature is having freely rotating
(electric) propulsion units on the ends of the payload frame. The top
propellers may be used for pulling the ship up against the wind. If
there is significant wind, it will be advantageous to have a mooring
cable going along the wind direction.

The
mooring cable above the airship will protect the ship against
lightning in the critical phase when the ship is about to get ground
contact. It will also discharge static electrical charges in a
controlled manner. This is important if the ship uses inflammable
gases.

The
mooring operation is as follows:

The
airship approaches the mooring cable from below, having the rear
cable grabber pulled all the way to the front, and trying to align
its body with the cable.

When
sufficiently aligned under the cable, the ship moves straight
upwards, so that the cable is caught in the bottom of the V-shaped
structure, and both cable grabbers can grab the cable.

The
front grabber holds the cable firmly, and the rear grabber moves
backwards to the rear end of the ship, securing also against
rotation (jaw and pitch).

The
ship moves to the passenger platform, either by loosening its cable
grips and using propeller propulsion, or by being pulled in by a
moving cable.

If
the payload frame now moves in under a tongue-shaped roof, this roof
will act as a firewall which increases the safety when inflammable
gases are used in balloons. (Gas flames go upwards, but burning
balloon parts fall down.)

The
near end of the mooring cable is then lowered until the cabins sit on
the platform. The side edges of the roof will be near the straps
under which the payload frame hangs, so these side edges should be
able to hold the straps firmly – to keep the cabins in moored
position.

(A
simple but crude mooring method would be to let the airship move
forwards/downwards into the space between two fences. Such a fence
can be a wind screen or a cable fence with at least one horizontal
cable. But both fences must be able to yield rapidly if the ship is
blown forcefully to the side before it is properly between the
fences.)

During
take-off, the sequence of cable grabbing events is reversed: First
the cable leads the ship outwards, and then the aft cable grabber
goes forwards and loosens its grip, so that the ship turns against
the wind and can fly away in a well-controlled manner.

As
airships need no runways, the airports can be so compact that they
can be near a city center. For a coastal city, airships could
approach along cables running from a tower out in the sea. The entire
airport could be on a platform or a float outside the coast. The
airport and the approach cable could also be shielded between tall
buildings, small mountains, or wind screens.

Operation

The
multi-mode airship can start with simple balloon flight operation –
with passengers who just want to go up and look around. An extra
balcony module in the payload frame (or upon the roof of the cabin)
will now be valuable.

The
electric propulsion of the payload frame motors will now prove
important: Conventional noisy motors will destroy the whole soaring
experience.

The
next operation will be cruises to (and at) specific destinations –
when steerability is found reliable, and a destination service
infrastructure is established. Only simple mooring facilities will be
needed by the airship itself, in addition to gas delivery and a power
grid connection for recharging the batteries.

If
this operation is found reliable, regular passenger transport can
commence. This will compete with trains and conventional airplanes. A
suitable operation area will be: across the North sea, across the
Baltic sea, and similar areas unsuitable for trains. The competitor
will now be the airplane. The airship will be more like a train with
respect to bomb sensitivity – particularly if separate luggage
modules are mounted in the payload frame. Much security control time
can then be saved, particularly if passengers can remain seated in
cabins transported by a beamway
from and to city centers.

The
airship can give the passengers more space (in lightweight cabins)
than planes can, so it can have decent sleeping quarters. This means
the airship may be preferred for quite long night flights.

Sustainable
tourism implies changing attitude towards travelling. The prevalent
businesslike practice of jumping to a remote place should be
discarded, and be replaced by accepting that travelling implies being
on the way. Travellers from northern Europe should find it natural
that if they intend to visit south Asia, they will start and end the
vacation with spending at least one day in the Mediterranean area.

Operation
economy should be ensured when polluting and CO2-emitting
aviation is appropriately taxed.

Long
Distances

An
airship could join an air train for long-distance flights. The
locomotive would be a turboprop plane flying non-stop between e.g.
England and the US east coast. It reels out aft a carbon cable, 1-2
kilometers long, to which airships can attach themselves when the air
loc slows down to perhaps 100 km/h over England. After an airship has
grabbed the cable, it can move forwards towards the preceding one, so
such a train could get a moderate air resistance. The train will then
increase the speed to perhaps 6-700 km/h, suitable for an overnight
journey with berths/sleeperettes. In the New York area, the airships
will detach in the reversed order, and some of them may continue to
Boston or Washington DC. Other airships will then attach for the
eastbound flight – or for going to the west coast. Daytime
long-distance flights may be more suitable for cargo. Before an
airship joins the train, it may visit a transit platform where
passengers may go over to the airship for the right destination.
Personnel who do on board custom/passport/security controls may be
exchanged there. They can get decent space for their work on an
airship. Such operations will be quite simple with airships, as they
have VTOL capability.

Two
airships (solar cell covered) have attached themselves to the cable
of an air train.The rightmost one has now pulled its rear cable
grabber all the way back, so it is fully stabilized.

The
first airship attaching will probably be for fueling and crew
exchange. The air loc flight will probably become quite computer
controlled. Air locs with abundant energy can easily give some of it
to the airships. The cable could transmit electric power both ways,
but the simplest way to get power from the air loc would be to simply
use the electric propulsion motors as generators and their propellers
as windmills. If the airships have much energy (in sunlight), they
can contribute to the propulsion by running their propulsion frame
propellers.

The
air loc should be able to fly at 100-700 km/h, so a variable wing may
be required. A small drone with stabilizing fins or wings should be
attached to the other end of the cable. It will have a variable pitch
propeller, and this should have three operating modes:

Blades
turned for giving maximum air resistance – while airships are
attaching/detaching

The
air loc could be pulling a shield which can be opened and closed like
a flower. It is closed like a bud for take-off and landing. For
normal flight, it is opened to be a shield in front of the first
airship – to relieve it of the speed wind pressure.

An
alternative to the air train is the air caravan: An airship goes in
the front, equipped with a reinforced front plate, and it carries the
cable assembly instead of a passenger cabin. The caravan will be
mainly for daytime operation, as all the airships must use their
propulsion systems.

Biefelt-Brown
Propulsion

Such
long trains are well suited for electric field propulsion based on
the Biefelt-Brown
effect. This could be done in two ways:

For
each airship individually, as mentioned above: by applying high
voltages to parts of the canopy. These voltages will to some extent
be added up by a series connection – like in T. T. Brown's
gravitator.

By
applying a positive voltage to the locomotive and a negative voltage
to the rear drone. If air is ionized, the total electric dipole
strength will be reduced by an ionic short-circuit, but if the train
can fly in 700 km/h, ionized air may not manage to fly to the
oppositely charged pole.

The
air loc with the positive electrode should be at least 100 meters
ahead of the first airship, or the first airship in a caravan should
have a positively charged shield. (Intermediate airships may be given
intermediate voltages, but in the non-linear manner required for the
Biefelt-Brown effect: strongest gradient behind at the negative
pole.) Either of these two would enable the train, with its field and
ionized air, to behave as a large streamlined entity which would
protect each airship against the strong speed wind. (This design
sketch doesn't take side in the electrogravity vs. ion wind schism.)

Safety
and Security

The
airship will hopefully be as explosion resistant as a train or
beamway, so that it will not be more interesting for terrorists than
any other meeting place – particularly if luggage is placed in
a separate container module. This will reduce the security control
delays to a minimum. Customs and passport control could be done on
the airship, as this will be roomier than a plane, and may even have
a separate office module for such controls. Undesired
passengers/luggage can be removed during a transit platform visit.

A
balloon will be easy (and tempting) to shoot a hole through, but it
may be designed to be made self-repairing: The inside of its fabric
could be covered with a low-density sticky plastic foam which will be
caused to form a patch by out-streaming gases in a hole. If one of
the three balloons is destroyed, the VTOL propulsion units may be
able to give a not too hard landing – and/or the airship will
open up to go into parachute or paraglider mode.

It
may be feasible to make carbon fiber armored balloons bullet-proof,
because the fabric needn't be very strong. This is because of its
unique ability to yield rapidly to a sudden local impact, as a light
gas behind the fabric will only weakly resist the sudden
acceleration.

The
use of fuel gas is likely to be restricted to cargo flights, but it
might be found usable for passenger flights: A fire in a fuel gas
balloon will occur some distance above passenger cabin –
particularly when the airship is in an open mode. The strength of the
canopy should be based on carbon fibers, which are able to withstand
high temperatures, so the airship may still be able to function in
parachute or paraglider mode during and after a gas fire. If not,
cabins should bail out in their own parachutes. Cabins should be
designed to stay afloat if they land in the sea, either by having
thick and light floor and lower walls, or by having self-inflating
floaters.

In
contrast to the conventional all in one airship design, the present
design separates the passengers from the balloons, so that both
sabotage and cargo explosion damage will be a smaller threat to the
ship.

An
airship should be boardable from anti-terrorist helicopters, and is
not easily crashed, so it would not be suitable for hijacking.

VTOL
operation is normally a precarious balancing act, but will be a
simple and safe operation for an airship, which will always be kept
upright by its balloons.

Police
Operations

Helicopters
are useful for various police operations, but due to their complexity
and risky operations, only the large police departments in
metropolitan areas can have helicopters. This was demonstrated during
the terrorist attack in Norway on July 22. 2011. The police in Oslo
had a helicopter, but no staff able to use it due to the summer
vacation. Criminals will of cause notice this and strike in the
periods of weakness. The solution will be to use airships instead of
helicopters, because airships can be running in passenger transport,
particularly across the sea stretches of northern and southern
Europe. Through a cooperation between the police and airship
companies, an airship can be requested for police action while the
special police unit is preparing for action.

Shooting
down a helium-filled airship is a slow process, and may be really
difficult to do with light weapons from the ground if the airship
fires guided missiles from a high altitude.

An
airship is an asymmetrical weapon, as it is impractical to have and
to use airships for crimes, e.g. as a getaway vehicle, even if the
criminals intend to switch to a car.

Needed
during Volcanic Activity

During the
eruption of the Icelandic volcano Eyjafjallajökull in the spring
of 2010, the air traffic over most of western Europe was halted for
days – because the jet motors of the planes couldn't deal with
the airborne ashes.

The
airship's electric motors will be able to withstand large amounts of
such particles. Besides, the “raincoat” of this ship will
give protection against quite warm and heavy particle falls.

This
may seem rather unimportant now, but when the supervolcano under
Yellowstone explodes (– any year now), much heavier ash falls
will persist worldwide for years, and such alternative air transport
will really be needed.

Buoyancy
Calculations

The
balloons shown in the illustrations have the following volumes:

23
000 m3 for the middle balloon (102 meters long)

18
500 m3 for each side balloon (89 meters long)

Total
volume: 60 000 m3. If the middle balloon is filled with a
fuel gas, total volume is reduced to 39 300 m3 when 90 %
of this gas (20 700 m3) has been burnt up.

Gas
Property \

Air

HydrogenH2

HeliumHe

MethaneCH4

Natural
gas

EthaneC2H6

Molecular
weight (average)

29

2

4

16

17-18

30

Buoyancy
(mol. weight)

0

27

25

13

11-12

-1

Buoyancy,
kg/m3

0

1.205

1.116

.580

.5

-.045

Buoyancy
in tons*for 60 000 m3for 39 300 m3

6944

67

54.642.6

5342.4

40.341.2

Combustion
energyfor 1 m3

25.5 MJ

36 MJ

39 MJ

70
MJ

Combustion
energyfor 20 700 m3

528 GJ147
MWh

740 GJ206
MWh

807 GJ224
MWh

1448 GJ402
MWh

*:
with helium in the side balloons, which will then contribute with
lifting 41.3 tons